The invention relates to a machine tool for machining rotating workpieces by means of a tool, especially a fly cutter, rotatably driven in synchronization with the workpiece, for producing teeth, with workpiece drive and tool drive being kept in synchronism by respectively associated rotation transmitters by means of electronic control means, with a positioning motor being associated with one of the two drives for influencing the position of the phases of the two drives.
In a known device of this kind (DE 41 14 341 C2), the stator housing at least of the one motor is mounted concentrically with respect to the motor axis and is rotationally adjustable around this axis by means of the positioning motor. This means that the positioning motor is actively engaged forcewise in the power flow of the drive and must therefore be dimensioned to be sufficiently strong.